System and method for improved media identification in a storage device

ABSTRACT

Systems and methods are provided for improved identification of removable storage media. A scanner may be used to read an identifier, such as a barcode, on a removable storage media. In the event that the scanner reads the identifier incorrectly due to a defect in the barcode, such as a damaged label, misaligned identifier, or because the scanner is incapable of reading the identifier type or the scanner&#39;s field of view is incorrect, a media management component receives the scanned identifier data and matches it to a known set of media identifiers to create a subset of matching identifier data. A closest matching media identifier may be identified from the subset of matching identifier data. An index may be updated with information indicating the closest matching media identifier and a location of the removable storage media.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. patent application Ser. No.12/372,081, titled SYSTEM AND METHOD FOR IMPROVED MEDIA IDENTIFICATIONIN A STORAGE DEVICE, filed Feb. 17, 2009, now U.S. Pat. No. 7,739,450,which is a continuation of U.S. patent application Ser. No. 11/313,267,titled SYSTEM AND METHOD FOR IMPROVED MEDIA IDENTIFICATION IN A STORAGEDEVICE, filed Dec. 19, 2005, now U.S. Pat. No. 7,603,518, both of whichare hereby incorporated herein by reference in their entireties. Thisapplication is related to the following pending applications, each ofwhich is hereby incorporated herein by reference in its entirety:

-   -   application Ser. No. 10/819,102, titled SYSTEM FOR CONTROLLING A        ROBOTIC ARM IN A STORAGE DEVICE, filed Apr. 5, 2004, abandoned;    -   application Ser. No. 10/663,383, titled SYSTEM AND METHOD FOR        BLIND MEDIA SUPPORT, filed Sep. 16, 2003, now U.S. Pat. No.        7,162,496;    -   application Ser. No. 10/260,209, titled SYSTEM AND METHOD FOR        ARCHIVING OBJECTS IN AN INFORMATION STORE, filed Sep. 30, 2002,        now U.S. Pat. No. 7,107,298; and    -   application Ser. No. 09/610,738, titled MODULAR BACKUP AND        RETRIEVAL SYSTEM USED IN CONJUNCTION WITH A STORAGE AREA        NETWORK, filed Jul. 6, 2000, now U.S. Pat. No. 7,035,880.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosures, as it appears in the Patent and TrademarkOffice patent files or records, but otherwise reserves all copyrightrights whatsoever.

BACKGROUND

The invention disclosed herein relates generally to improvedidentification of media identifiers.

Removable media storage devices such as tape libraries, opticallibraries, and CD-ROM jukeboxes are frequently used for storage ofelectronic data generated by client computers. A removable media storagedevice generally includes removable media such as tape cartridges,optical disks, or CD-ROMS and may also include a mechanism, such as arobotic arm, that moves the removable media into and out of a drivewhere content of the media may be read or updated.

Removable media may include an identifier which may be affixed to themedia, such as a hand printed label, machine-readable barcode, or otheridentifier. The media identifier generally contains information naming,indicating, distinguishing or otherwise identifying the media. The useof barcodes to identify removable media allows storage devices tooperate autonomously with greater efficiency. For example, a removablemedia storage device equipped with a barcode reader may identify andselect a removable media for a storage operation based on the respectivebarcode. A storage device with a barcode reader may automaticallyidentify a specific item of removable media according to the barcodethereon and insert the removable media in a corresponding drive toperform a storage operation. Thus, a storage operation can proceedaccording to predefined schedules and criteria with minimal operatorintervention resulting in greater efficiency.

There are several types of barcodes. In general, a typical barcodeincludes a series of vertical lines or other graphical indicators whichcorrespond to a code comprising alphanumeric characters. Barcodes can beread by optical scanners which scan the vertical lines forming abarcode. Barcodes applied to media are generally a standard length, suchas six or eight characters, which may be in accordance with ANSI/AIMstandards.

Some optical scanners that read barcodes may be capable of reading onlyone type of barcode, or only barcodes of a particular length. When a newmedia item, such as a tape cartridge, optical disk, or CD-ROM is addedto a storage device that has such an optical scanner, the mediaidentifier information may not be readable by the scanner. This mayoccur when using new barcoded media items in a legacy storage device.For example, an older scanner in the legacy storage device may not beequipped to process new barcodes. To avoid such problems, a storagemanagement systems may be limited to using certain barcoded media, oralternatively, the optical scanner may be replaced or upgraded.

In addition to scanner limitations, there may be problems with labels orfields of view for scanners that cause a scanner to read a mediaidentifier incorrectly. For example, a media identifier may lie outsideof a field of scan, and portions of the identifier may not be scanned,or a media identifier may be damaged, misaligned or otherwiseunreadable. For example, a label including a media identifier may beworn or placed in a position that may prevent the optical scanner fromreading the media identifier in its entirety. Thus only a portion of theidentifier is read and the media cannot be identified.

SUMMARY

The present invention relates to providing improved identification ofidentifiers, such as a barcode, for removable media. In one embodiment,a method for automatically identifying a removable media identifier isprovided in which data is received which indicates an identifier of aremovable medium. The received identifier may be a barcode, radiofrequency identification tag or other identifier. The receivedidentifier is compared with a set including a plurality of known mediaidentifiers to identify a subset of known media identifiers among theset including the plurality of known media identifiers which match thereceived identifier. The subset of known media identifiers may beidentified by matching a predefined number of characters of the receivedidentifier and the set including the plurality of known mediaidentifiers, or alternatively by matching a pattern of characters of thereceived identifier and the set including the plurality of known mediaidentifiers. The number of media identifiers included in the subset isdetermined to satisfy a threshold; and from the subset, a closest matchto the received identifier is identified. The threshold may beuser-defined or preset, for example, in accordance with a storage policyor template or other setting. An index entry for the closest matchidentifier may be updated indicating a location of the removable medium.

In another embodiment, a method for maintaining an index of removablemedia items is provided in which data is received, the data indicatingan identifier for a removable medium and indicating a location of theremovable medium. The identifier is matched to a set of known mediaidentifiers to generate a subset of media identifiers. A closest matchof the subset of media identifiers is determined and an index entry forthe closest matching identifier is updated with the location of theremovable medium. The location of the removable medium may be verified,in accordance with a storage policy, by scanning a media identifier onthe removable medium in a storage device; obtaining a current locationof the removable medium; and updating the index entry with the currentlocation of the removable medium.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a view of a media identifier onremovable media according to an embodiment of the invention;

FIG. 2 is a block diagram showing storage device components according toan embodiment of the invention;

FIG. 3 is a block diagram of a network architecture in accordance withone embodiment of the invention;

FIG. 4 is a block diagram depicting views of fields of scan of anoptical scanner according to an embodiment of the invention;

FIG. 5 is a flowchart depicting a method for tracking media according toone embodiment of the invention;

FIG. 6 is a flowchart depicting a method for identifying media accordingto one embodiment of the invention;

FIG. 7 is a block diagram depicting a view of subsets created bycomparing identifier patterns according to one embodiment of theinvention; and

FIG. 8 is a block diagram depicting a view of an association between amedia identifier as scanned and complete media identifier informationaccording to one embodiment of the invention.

DETAILED DESCRIPTION

The present invention relates to systems and methods for improvingidentification of removable media items in a storage device. Removablemedia items may include optical media, disks, tapes, magnetic media, orother removable media. One example of removable media is the tape 25depicted in FIG. 1. In general media may be removable if it can bedetached and removed from a storage device in which the media is used toperform reading or writing operations or other storage operations.Removable media is frequently used in storage management systems and isuseful for storing data or for performing other storage operations.Storage operations, as used herein, may include creating, storing,retrieving, and migrating primary storage data and secondary storagedata (which may include, for example, snapshot copies, backup copies,HSM copies, archive copies, and other types of copies of electronicdata) stored on storage devices.

As shown, removable media 25 may include an identifier 40, such as abarcode, which may comprise a series of vertical lines 47 or otherindicators which may correspond to an alphanumeric code 45. Mediaidentifier 40 may also comprise characters, a combination of numbers andcharacters, symbols, or other forms of identifiers and can be printed ona label or otherwise affixed to various media 25 surfaces. Thealphanumeric code 45 or the identifier 40 may be used as an identifierfor the media item 25 and used as a basis to track the media item 25,e.g., as a variable in an index, etc. Other forms of machine readableidentifiers may also be used on media 25, such as radio frequencyidentification (RFID) tags, or other item identifiers known in the art.

Existing storage devices which use removable media may include one ormore removable media items 25. For example, as shown in FIG. 2, astorage device 125 may include a plurality of media items 25, which maybe loaded to or ejected from slots 140 or drives 135 by a robotic arm130. The robotic arm 130 may include a scanner 145, such as an opticalscanner, RFID scanner, or other scanning device. Each of the elements ofthe storage device 125 may be any appropriate device known in the artcapable of performing a storage operation, for example, the media 25 canbe tapes, media cartridges, or other media capable of storing data, suchas Linear Tape Open (LTO) or Digital Linear Tape (DLT) tape cartridges.The drives 135 can be disk drives or other drives, such as HITACHI tapedrives, which are capable of receiving media 25 and reading and writingstored data on media 25.

The robotic arm 130 is generally capable of obtaining the media 25 froma slot 140 and loading it into a drive 135 and correspondingly capableof removing the media 25 from the drive 135 and replacing the media 25in a slot 140 in the storage device 125. A slot 140 may be a receptacleor space which may be occupied by a media item 25. In general, the slot140 does not have the reading or writing capability of a drive, and maybe simply a place to temporarily store or hold a media item 25. Eachslot 140 has an assigned location or name, which may be used, togetherwith a media identifier to track a location of a media item 25, forexample, in an index.

In general, a field of scan of a scanner 145 may be a physical range ofspace in which a scanner is capable of operating and receiving input,such as a range of space in which the scanner can scanning barcodes,etc. For example, the field of scan may be one or more rows or columnsof slots in a storage device, or may be a range of one or more tapes andidentifiers thereon. In some instances, a field of scan may not coverall or portions of an identifier on a tape or media item, for examplewhen a media identifier is relatively long. In other instances, thefield of scan may omit sections of rows or columns of media slots. Forexample, one field of scan 405 may capture only a middle portion ofmedia 25. Such field of scan 405 may fail to capture media identifierinformation which may lie outside of the field of scan, thus obtainingonly a portion of media identifier information. Capturing incompletemedia identifier data may cause identification of the media item 25 tofail because the incomplete identifier data cannot be matched with amedia identifier in a database of identifiers. In this case, a storagemanagement system may determine that the media item 25 is new because itcannot otherwise identify the media item 25 as a recognized media item25. This may be problematic because a storage management system may losedata by deleting, overwriting, or formatting the unrecognized media item25.

One storage management system used to perform the invention describedherein may be the storage management system depicted in FIG. 3, butother storage management system architectures may also be used. Asshown, a storage management system may include a storage manager 100,which includes an index 105, media management devices 115, which includea media management device index 118, and storage devices 125, whichinclude a robotic arm 130. The storage manager 100 can be a softwaremodule, which is capable of coordinating and controlling a storagesystem. For example, the storage manager 100 communicates with allcomponents of the storage system, including, for example, a mediamanagement device 115, to initiate, perform, and manage system backups,migrations, restores, and other storage-related operations.

The index 105 included in the storage manager 100 can be any index thatis maintained to store index data for each system storage operation,such as, the data the system generates during storage operations such asbackup, migration, configuration, restore, and other storage operationsas further described herein. The index 105 can also be a storage indexknown in the art, such as, for example, the index cache of CommVault'sGalaxy™ as further described in application Ser. No. 10/260,209 which isincorporated herein by reference in its entirety. The index 105 storesdata related to logical association controls, network pathways, andmaintaining hierarchies in system components. For example, the index 105may store data such as the relationships between a storage manager andcomponents of the storage system and the relationships between thecomponents of the storage system. In addition, the index 105 may storedata defining communication pathways between the storage systemcomponents. Index data is useful because, among other benefits, itprovides the system with an efficient mechanism for locating informationassociated with performing storage operations.

Each media management device 115 is associated with one or more storagedevices 125 and controls storage operations of the associated storagedevice 125. Each media management device 115 may also include an index118. The media management device index 118 may be used to store datarelating to media items, including, for example, data relating to themedia identifier, a location of a media item, information relating tothe data stored on the media, or other information relating to a mediaitem and data stored thereon.

The media management device 115 is communicatively coupled to a storagemanager 100 and a storage device 125. The media management device 115 iscapable of communicating instructions from the storage manager 100 to astorage device 125 to undertake a storage operation. For example, themedia management device 115 may instruct the storage device 125 toarchive, migrate, or restore stored data, perform a libraryconfiguration, or other storage operation. The media management devices115 may also conduct other data between the storage manager 100 and oneor more storage devices 125. The media management device 115 generallycommunicates with the storage device 125 via a local bus such as a SCSIadapter. In some embodiments, the storage device 125 is communicativelycoupled to the media management device 115 via a network such as aStorage Area Network (“SAN”), or a Local Area Network (“LAN”).

The barcodes 410 depicted in FIG. 4 comprise several vertical lines 320,each generally corresponding to an alphanumerical value or otheridentifier identified at the bottom of each vertical line 415. As shown,the barcodes 410 on media 25 are arranged in a storage device in threecolumns and three rows of slots. Any number of rows and columns of slotsmay be included in a storage device depending on a storage device type,storage requirements, etc., as may be appreciated by those skilled inthe art. An optical scanner 145 reading the barcodes 410 may scan theseries of vertical lines and translate the image data into acorresponding alphanumeric code. Barcodes 410 or other identifier may beassigned or associated with information about media 25, such as a mediaidentifier, type of media, size of the media, media capacity,manufacturer, or information relating to the data contained on themedia, such as data type, etc. Such information may be included in anindex, such as a media management component index, storage manager indexor index of a system component.

The barcode 410 or identifier may be used in connection with storageoperations to identify a media item. For example, a media managementcomponent may instruct a robotic arm to obtain a particular media itemfrom a particular location, and the robotic arm may use its scanner toscan the media item to confirm its identity. Alternatively, the barcode410 or media identifier may be used to scan all media items contained ina library or storage device, and provide information about mediaincluded therein. A scanner on the robotic arm may scan barcodes onmedia items to identify or confirm the identity of a media item. Asmentioned herein, some optical scanners may be incapable of readingcertain types of barcodes. Other optical scanners may encounter problemswith a field of scan. For example, a scanner may omit a tail end of abarcode, as shown in field of scan 405 a, a front end of a barcode, suchas the field of scan 405 b, both the front end and tail end of abarcode, as shown in field of scan 405 c, or the front and tail ends ofbarcodes on different rows of media items as shown in field of scan 405d. Other scanning problems may occur if a barcode or other identifierlabel is damaged, torn, smeared, or otherwise unreadable.

Media may be scanned and tracked according to the flow diagram depictedin FIG. 5. Media items may be received in a storage device, step 500,for example, when new or known media items are added to a storagedevice. For example, data contained on known media that has beenidentified for a restore or verification operation may be received in astorage device. The media items are scanned, step 510. The media itemsmay be scanned using a scanner, such as an optical scanner, RFID scanneror other scanning device. The scanner's field of view may cover all or apart of the length of the barcode or media identifier. The scanned mediaidentifier information is communicated from the optical scanner to amedia management component or other system component such as a storagemanager, and index data is consulted to determine whether the scannedmedia identifier is included in the index, step 520. For example, if amedia item is known to the media management component, storage manageror other system component, its identifier information may be stored inan index. In the event that the media item is new to the system, or inthe event that the media identifier may not be recognized, e.g., it isdamaged, or the scanning was defective, the new media identifier may beadded to the index. Alternatively, the correct identifier for theunrecognized media identifier may be obtained as further describedherein.

Information relating to the scanned media may be updated in the index,step 530. For example, information relating to the barcode or mediaidentifier, and location information may be stored to the index,including a slot location in a storage device, a storage device, orother location information. Other information relating to the media mayalso be included in the index, such as media type, information relatingto the data on the media, a storage policy for the media, mediacapacity, age of the data on the media, age of the media, or other data.

The media may be tracked 540, by maintaining the index with locationinformation and other information relating to the media. For example,location information may be updated when media moves from one locationto another location, is between slots in a storage device, moves fromone storage device to another storage device, moves from one slot toanother slot, etc. Media location information may be verified, step 550,for example, on an ongoing basis according to a storage policy byinitiating a configuration operation or other storage operation, inwhich a scanner in a storage device scans some or all media items in thestorage device and compares scanned identifier information and slot orother location information with media identifier and locationinformation in an index.

In some instances, scanned media items may not be recognized by a mediamanagement component or other system component because of a problem inscanning the media identifier. For example, as shown in FIG. 4, fieldsof view of a scanner may omit portions of a barcode or media identifier,or a scanner may be incapable of reading a particular type of barcode,or experience some other problem in scanning the media identifier.Alternatively, there may be a defect in a barcode, such as a damagedlabel, smudged barcode, or other defect that causes a scanner to readthe barcode incorrectly. In this case, an accurate or true identifierfor the scanned media identifier may be identified, as further describedherein.

An incorrectly scanned barcode, or a defective barcode may be identifiedaccording to the flow diagram of FIG. 6. As shown, a barcode or othermedia identifier on media may be scanned, step 705. The media may bescanned by a scanner, such as an optical scanner, RFID scanner or otherscanner. Scanned media identifier data may be compared to a set of knownmedia identifier data, step 710. In general, the set of known mediaidentifier data may be data stored in an index, such as a mediamanagement component index or storage manager index, or media identifierdata otherwise provided to a system component. A media managementcomponent, storage manager or other system component may perform thecomparison of the scanned media identifier data and the known set ofmedia identifier data to determine whether a match exists, step 715. Amatch need not be an exact match of identifier data values, and mayinclude a degree of correspondence among elements of the identifiers,such as a threshold range of identifier data values. If there is nomatch between the scanned media identifier data and known mediaidentifier data, the media management component or storage managerassumes that the scanned media item is new, and adds the new mediaidentifier to its index, step 720. The match threshold may be userdefined or pre-set and may range from a single alphanumeric charactermatch to a match of multiple alphanumeric characters.

The match for a comparison may include pattern matching, order matching,length matching, character type matching match, sum matching or othermatching. One example of a match may be that a pattern of threecharacters appearing in a six character media identifier scanned in thestorage device must appear in the eight character index media identifierdata set. Alternatively, the match may require that four charactersappearing in consecutive order in a six character media identifier mustappear in the same consecutive order in an eight character mediaidentifier. Yet another match may be that the length of a scanned mediaidentifier must be the same as the length of the media identifier datastored in the media management device index or storage manager index. Afurther match may be that alphanumeric characters appearing in certainpositions of a scanned media identifier must correspond to alphanumericcharacters appearing in the same positions of a media identifier storedin the storage manager index or media management device index. If ascanned media identifier corresponds to the code “A142B”, in order for amatch to exist, a second media identifier must contain a letter in thefirst position, a numerical value in the second, third and fourthpositions, followed by a letter in the fifth position. Moreover, thematch may require the sum of alphanumeric characters comprising ascanned media identifier to equal the sum of the alphanumeric characterscomprising an index media identifier. If the scanned media identifier orindex media identifier are comprised of both numerical and non-numericalvalues, a conversion to numerical values using ASCII values or otherconversion methods known to those with ordinary skill in the art may beused.

If a match exists, which may be that a single alphanumeric value thatcorresponds to the scanned media identifier matches a singlealphanumeric value in a set of known media identifiers, a mediamanagement component determines the number of media items in the knownset which match the scanned media identifier, step 725. Matching may beperformed to narrow a set of results. For example, as shown in FIG. 7, amedia item 810 may be scanned which includes the identifier “857872”.The identifier may be matched to all media identifiers in a known set,such as set 820. A four character match set 840 may be obtained, inwhich all media items in the known set 820 having four characters thatmatch the scanned media identifier 810 are provided in a subset 845. Asshown, the character match may be according to the scanned pattern, orfour matching characters in any order, or other matching technique. Themedia items may be further compared, to obtain a five character match855 subset 860, a six character match 870 subset 875, or furthercharacter match, according to a user defined or automatic pre-setmatching.

Referring again to FIG. 6, the media management component determineswhether the number of matching media items satisfies a threshold, step730. A threshold for a number of matching media items may be userdefined, or automatically preset. For example, a threshold may bedefined whereby a subset of matched media identifiers cannot exceedtwenty items. Thus, if a match of a scanned media identifier and a setof known media identifiers yields a subset of twenty two mediaidentifiers, the media item is assumed to be new and added to an index.

If, however, the subset of matched media identifiers is fewer thantwenty, a closest matching media identifier may be identified, step 735.As shown in FIG. 7, a best match set of one media identifier 890 may beobtained by selecting a media identifier having a number of matchingcharacters which appear in the same consecutive order as the scannedmedia identifier characters. Other matching patterns may be used toidentify a best match, such as the media item having the greatest numberof matching characters, a closest character order match, or otherpattern matching which may include recognizing characters likely to bemisread, such as a “3” misread as an “8”, a “7” misread as a “1”, orother matching. Other criteria may also be used to select a best match,based on the media identifier characters, or data relating to the mediaitself, such as a media type, or other criteria. Referring again to FIG.6, an index, such as a media management component index or storagemanager index may be updated with the best match media identifier andscanned media item data, step 740. In addition, a user may be notifiedof the matching media item.

Referring to FIG. 8, an incomplete media identifier in a set of scannedmedia identifiers 910 may be associated with a respective set ofcomplete or accurate media identifiers 900. The set of media identifiers900 may, for example, comprise index data including entries for certainmedia items known to the system, storage manager or other systemcomponent, including media identifiers 901, 902 and 903. The incorrectlyscanned media identifiers 9010, 9020, 9030 which are scanned with adefect in reading portions of a tail end, front end and middle,respectively, of the identifiers, may be associated with its respectiveaccurate identifier via a link, pointer, or other association means,9012, 9022, 9032. For example, an item 9010 having a scanned identifier“580084” may provide a front portion of an identifier, but which may belinked 9012 to an accurate item 901 which has a full or accurateidentifier “58008493”. In another example, item 9020 may have beenscanned incorrectly and the beginning of the identifier may have beenomitted so that “708578” is scanned. A link 9022 may be provided to theaccurate identifier 902, “98708578”. In yet another example, item 9030may be scanned and a middle portion of the identifier is omitted, whichmay occur, for example, if there is a smudge or tear on the identifiersurface and the scanned identifier is “012(---)47”. A link 9032 may beprovided to the accurate identifier 903, “01250147”.

Each media item 910 contained in a storage device 905 may be scanned bya scanner on a robotic arm 906 and a scanned media identifier 908 may becommunicated from the storage device 905 to a media managementcomponent, which may store the media identifier set of data 910 in itsindex, or alternatively in a storage manager index. Although FIG. 8depicts two tables in a relational database, it is understood that otherindexes, tables or other methods may be used to track relationshipsbetween identifier data.

While the invention has been described and illustrated in connectionwith preferred embodiments, many variations and modifications as will beevident to those skilled in the art may be made without departing fromthe spirit and scope of the invention, and the invention is thus not tobe limited to the precise details of methodology or construction setforth above as such variations and modifications are intended to beincluded within the scope of the invention.

1. A method for maintaining an index of removable storage media items,the method comprising: receiving data indicating an identifier for aremovable storage media; receiving data indicating a location of theremovable storage media; matching the identifier with a set of knownmedia identifiers to generate a subset of media identifiers; determiningat least one closest match of the subset of media identifiers and theidentifier; and updating an index entry for the at least one closestmatch of the subset of media identifiers with the location of theremovable storage media.
 2. The method of claim 1 further comprising:according to a storage policy, verifying the location of the removablestorage media, wherein verifying the location of the removable storagemedia comprises: scanning a media identifier on the removable storagemedia in a storage device; obtaining a current location of the removablestorage media; and updating the index entry with the current location ofthe removable storage media.
 3. A computer readable medium includingcomputer executable code, which when executed causes a computer toperform a method for automatically identifying a removable storage mediaidentifier, the method comprising: receiving data indicating anidentifier of a removable storage media; comparing the receivedidentifier with a set of known media identifiers; identifying a subsetof known media identifiers among the set of known media identifierswhich match the received identifier; and identifying at least oneclosest match among the subset of known media identifiers to thereceived identifier.
 4. The computer readable medium of claim 3comprising determining that the number of media identifiers included inthe subset satisfies a threshold.
 5. The computer readable medium ofclaim 3 wherein the received identifier comprises a barcode.
 6. Thecomputer readable medium of claim 3 wherein the received identifiercomprises a radio frequency identification tag.
 7. The computer readablemedium of claim 3 wherein the threshold is user defined.
 8. The computerreadable medium of claim 3 wherein the threshold is pre-set.
 9. Thecomputer readable medium of claim 3 wherein the subset is identified bymatching a predefined number of characters of the received identifierand the set of known media identifiers.
 10. The computer readable mediumof claim 3 wherein the subset is identified by matching a pattern ofcharacters of the received identifier and the set of known mediaidentifiers.
 11. The computer readable medium of claim 3 furthercomprising receiving data indicating a location of the removable storagemedia; and updating an index entry for the closest match mediaidentifier with the data indicating the location of the removablestorage media.
 12. A computer readable medium including computerexecutable code, which when executed causes a computer to perform amethod for maintaining an index of removable storage media items, themethod comprising: receiving data indicating an identifier for aremovable storage media; receiving data indicating a location of theremovable storage media; matching the identifier with a set of knownmedia identifiers to generate a subset of media identifiers; determiningat least a closest match of the subset of media identifiers and theidentifier; and updating an index entry for the closest match of thesubset of media identifiers with the location of the removable storagemedia.
 13. The computer readable medium of claim 12 further comprising:according to a storage policy, verifying the location of the removablestorage media, wherein verifying the location of the removable storagemedia comprises: scanning a media identifier on the removable storagemedia in a storage device; obtaining a current location of the removablestorage media; and updating the index entry with the current location ofthe removable storage media.